Problem with ORDER BY and random() ?

Hello,

I'm trying to retrieve a limited number of random rows, and order them by a
column, and am not having any luck with that last part:

SELECT * FROM tablename ORDER BY random(), id LIMIT 10

Returns everything more or less as expected, except for the fact that the
results aren't sorted by "id" ...

I also tried:

SELECT random() as sorter, * FROM tablename ORDER BY sorter, id LIMIT 10

But that didn't change anything either.

I tried sorting on a column other than "id", but that didn't work any better
:(

I also tried this on 7.2.1 and 7.3.1 (Both on RH 7.3), thinking this
might've been a bug.

A quick read of the docs suggests sorting on multiple columns is perfectly
legal, as it is used as an example.

atlas=# select id from quiz_questions_english order by random(), id limit
10;
id
-----
445
756
393
809
335
682
776
754
379
739
(10 rows)

atlas=# select random() as sorter, id from quiz_questions_english order by
sorter, id limit 10;
sorter | id
----------------------+-----
0.000757388770932978 | 455
0.00806515943634564 | 440
0.00836807396652553 | 386
0.00977775268711976 | 323
0.0104504898239162 | 370
0.0166072882789221 | 778
0.0202831137088514 | 416
0.0306016304672703 | 762
0.0340994806187691 | 772
0.0384632679812905 | 371
(10 rows)

Anybody know what's going on here ? I've tried this from Zope/psycopg,
pgAdminII, and psql ... removing the limit doesn't do any good, and neither
does using ASC or DESC !

Any help would be greatly appreciated !!

Thanks in advance,

Jean-François Doyon
Internet Service Development and Systems Support
GeoAccess Division
Canadian Center for Remote Sensing
Natural Resources Canada
http://atlas.gc.ca
Phone: (613) 992-4902
Fax: (613) 947-2410